How to judge which way the current is flowing in the second year of junior high school

The current is generated because of the potential difference.

In a simple circuit, the current flows from the positive electrode.

If there are multiple consumers in two branches, and there is a connection between the branches, the voltage of each power is obtained by resistor, and the current will flow from one of the consumers in one branch to the other branch lower than it (the current always starts from the positive end of the power supply).

Note that if there is a wire (i.e. no electrical consumer) directly connected to the electrical consumer, there will be no current passing through the electrical consumer, and the current will only flow through the wire.

The prescribed current flows out of the positive electrode and flows in the negative electrode, and when it encounters a fork in the road, it is divided into two ways.

Note: If there is no electrical appliance in one route (resistance is counted as electrical appliance (voltmeter is equivalent to an open circuit, so the current direction is not marked)), then the other road can basically not mark the current direction.

When you find that there is a point that makes several currents converge, that is the confluence point, and then connect all the way to the negative electrode.

The battery circuit where the current flows out of the positive electrode can be remembered on this junior high stage.

In the 19th century, when physicists first began to study electric currents, they did not know exactly what charges were moving in various situations, and at that time they defined the direction of positive charge movement as the direction of the current

According to this regulation, when the current is closed, the direction of the current is from the positive pole of the power supply through the consumer to the negative pole outside the current.

If there are electrical appliances in both branches, go both. If a branch has electrical appliances and a branch does not, the current will choose the road without electrical appliances, and then the branch with electrical appliances will not have current to pass, which is called being short-circuited - short-circuited by another branch (i.e., a wire) that does not use electrical appliances.

At the fork, the unused electrical appliances are short-circuited, which is equivalent to no obstruction, and the useful electrical appliances are resistive, which is equivalent to the current being hindered, so the current flows to the branch of the useless electrical appliances. Give it the best

The directional direction of movement of the charge is the direction of the electric current. However, for the convenience of research, it is stipulated that the direction of directional movement of the positive charge is the direction of the current.

There is a detailed explanation of the right-hand rule, you can take a look in advance if you don't understand, you can understand the flow direction, if you want to confirm the answer, it is best to have a multimeter, and you can easily understand the law by taking the test.

The circuit diagram is too vague to see clearly, which one to re-label the state:

The ammeter A1 measures the total current of L1 and L2, and the Daqiao A2 measures the current of L2.

Please, it's the ammeter A2 that measures the current, the ammeter A1 (on the right) is the power supply, and the ammeter A2 on the left measures the bulb L2.

First of all, correct your Hongyun macro question: Is the current measured by ammeter A2 the bulb L2 or the power supply current?

The current measured by the ammeter A2 is the current of the bulb L2.

From the figure, it can be seen that the bulb L1 and the bulb L2 are connected in series; And the ammeter A1 is on the main road, and the ammeter A2 is on the branch road.

Therefore, ammeter A1 measures the current of the power supply, and ammeter A2 measures the current of the bulb L2 (physics in the second year of junior high school).

Note: There is no such thing as a mains current, it is usually referred to as "dry current".

The current of L2 is measured.

Through L2, the landlord, your physics is so bad, hurry up and find a teacher to make up for it. The second volume of the eighth grade is all about electricity, so don't fall behind.

It's L2, and the ammeter L2 and the bulb L2 are connected in series!

A2 measures L2 current, L1 and L2 form a parallel circuit, and A1 measures the total current.

The diagram shows the direction of the current (forgive me for drawing it).

Generally, the problem of making circuits is mostly to spend current.

The ammeter measures the current of the electrical appliances on the standard series circuit.

The bulb in series with A2 is L2

So A2 measures the current of L2.

Yes measure the current in L2! Because A1 measures the current of the whole circuit !

A2 measures the current of L2, L1 L2 forms a parallel circuit, A2 measures the current on the branch where L2 is located, and A1 measures the total current.

A2 measures the current of L2, because this circuit diagram represents a parallel circuit, A2 and L2 are connected in series on a branch, so A2 measures the current of L2.

The original circuit can be redrawn to the circuit diagram shown below.

Therefore, A1 measures the current of the dry circuit and A2 measures the current of L2.

A2 measures L2 current, L1 and L2 form a parallel circuit, and A1 measures the total current.

A1 is the total current measured, and A2 is the current measured L2.

I like physics the most, if you guys like it.

Let's discuss.

A2 measures L2 because A2 and L2 are on the same branch.

It is not necessary to separate every branch point, for example, in the event of a short circuit, the branch that is short-circuited will have no current.

A local short circuit is when only a part of the entire circuit is short-circuited.

Short circuit refers to all short circuits, including local short circuits.

For example, in the following figure, after the switch is closed, there is a short circuit.

The circuit below is a local short circuit.

Your question is, to put it bluntly, how to judge a short circuit.

Judgment method: If the two ends of the electrical appliance are directly connected with wires, the current passes through the wire without passing through the electrical appliances, and the electrical appliances are short-circuited at this time.

I don't know how to ask I hope mine is helpful to you, o( o!

To string it is to wear it like meat on a lamb skewer.

Parallel is like a row of lamb skewers placed on the oven.

A short circuit is when the positive current flows directly to the negative electrode and can overheat at the power supply and create a danger.

A local short circuit is a partial short circuit in series.

A: You'd better give specific questions. The method of determining the direction of the current can be determined by different directions depending on the specific problem. For example:

1.According to the positive and negative poles of the power supply. Outside the power supply, the current direction is the positive and negative electrode of the consumer; Inside the power supply: negative and positive.

2.Moves according to the orientation of the charge. It moves in the same direction as the positive charge. It moves in the opposite direction to the negative charge.

3.According to the magnetic inductance lines around the current. This is determined by the right-hand spiral rule (or other rules).

4.It is determined by the interaction of the electromagnet with other magnets and the right-hand helix rule.

Generally speaking, it flows from the positive electrode to the negative electrode.

If it's an electromagnetic problem, look at how the coil is wound or by the magnetic poles.

On the outside of a dry cell battery (or power supply), current always flows out of the positive pole of the power supply, passes through the electrical appliance, and returns to the negative pole of the power supply.

Current flows from the positive to the negative of the power supply.